TITLE: GCN CIRCULAR NUMBER: 42826 SUBJECT: GRB 251124b: Fermi GBM Final Real-time Localization DATE: 25/11/24 17:34:45 GMT FROM: Fermi GBM Team at MSFC/Fermi-GBM do_not_reply@GIOC.nsstc.nasa.gov

The Fermi GBM team reports the detection of a likely LONG GRB

At 12:58:03 UT on 24 Nov 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 251124b (trigger 785681888.46989 / 251124540).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 262.1, Dec = 18.4 (J2000 degrees, equivalent to J2000 17h 28m, 18d 23'), with a statistical uncertainty of 13.1 degrees.

The angle from the Fermi LAT boresight is 52.0 degrees.

The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn251124540/q...

The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn251124540/q...

The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn251124540/q...

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